Improvements to dts emit for tsbuildinfo (microsoft#43205)

* Test update

* Use source file version as default signature for the file whenever there is no dts emit for the file

* json source files from project reference should be able to calculate the signature

* Dont emit declaration map when emitting dts files for force emit for signature

Author: sheetalkamat

src/compiler/builderState.ts

@@ -316,16 +316,8 @@ namespace ts {
             if (!info) return Debug.fail();
 
             const prevSignature = info.signature;
-            let latestSignature: string;
-            if (sourceFile.isDeclarationFile) {
-                latestSignature = sourceFile.version;
-                if (exportedModulesMapCache && latestSignature !== prevSignature) {
-                    // All the references in this file are exported
-                    const references = state.referencedMap ? state.referencedMap.get(sourceFile.resolvedPath) : undefined;
-                    exportedModulesMapCache.set(sourceFile.resolvedPath, references || false);
-                }
-            }
-            else {
+            let latestSignature: string | undefined;
+            if (!sourceFile.isDeclarationFile) {
                 const emitOutput = getFileEmitOutput(
                     programOfThisState,
                     sourceFile,
@@ -334,25 +326,26 @@ namespace ts {
                     /*customTransformers*/ undefined,
                     /*forceDtsEmit*/ true
                 );
-                const firstDts = emitOutput.outputFiles &&
-                    programOfThisState.getCompilerOptions().declarationMap ?
-                    emitOutput.outputFiles.length > 1 ? emitOutput.outputFiles[1] : undefined :
-                    emitOutput.outputFiles.length > 0 ? emitOutput.outputFiles[0] : undefined;
+                const firstDts = firstOrUndefined(emitOutput.outputFiles);
                 if (firstDts) {
                     Debug.assert(fileExtensionIs(firstDts.name, Extension.Dts), "File extension for signature expected to be dts", () => `Found: ${getAnyExtensionFromPath(firstDts.name)} for ${firstDts.name}:: All output files: ${JSON.stringify(emitOutput.outputFiles.map(f => f.name))}`);
                     latestSignature = (computeHash || generateDjb2Hash)(firstDts.text);
                     if (exportedModulesMapCache && latestSignature !== prevSignature) {
                         updateExportedModules(sourceFile, emitOutput.exportedModulesFromDeclarationEmit, exportedModulesMapCache);
                     }
                 }
-                else {
-                    latestSignature = prevSignature!; // TODO: GH#18217
+            }
+            // Default is to use file version as signature
+            if (latestSignature === undefined) {
+                latestSignature = sourceFile.version;
+                if (exportedModulesMapCache && latestSignature !== prevSignature) {
+                    // All the references in this file are exported
+                    const references = state.referencedMap ? state.referencedMap.get(sourceFile.resolvedPath) : undefined;
+                    exportedModulesMapCache.set(sourceFile.resolvedPath, references || false);
                 }
-
             }
             cacheToUpdateSignature.set(sourceFile.resolvedPath, latestSignature);
-
-            return !prevSignature || latestSignature !== prevSignature;
+            return latestSignature !== prevSignature;
         }
 
         /**

src/compiler/emitter.ts

@@ -498,7 +498,7 @@ namespace ts {
                     declarationTransform.transformed[0],
                     declarationPrinter,
                     {
-                        sourceMap: compilerOptions.declarationMap,
+                        sourceMap: !forceDtsEmit && compilerOptions.declarationMap,
                         sourceRoot: compilerOptions.sourceRoot,
                         mapRoot: compilerOptions.mapRoot,
                         extendedDiagnostics: compilerOptions.extendedDiagnostics,

src/compiler/utilities.ts

@@ -4215,8 +4215,10 @@ namespace ts {
         return !(options.noEmitForJsFiles && isSourceFileJS(sourceFile)) &&
             !sourceFile.isDeclarationFile &&
             !host.isSourceFileFromExternalLibrary(sourceFile) &&
-            !(isJsonSourceFile(sourceFile) && host.getResolvedProjectReferenceToRedirect(sourceFile.fileName)) &&
-            (forceDtsEmit || !host.isSourceOfProjectReferenceRedirect(sourceFile.fileName));
+            (forceDtsEmit || (
+                !(isJsonSourceFile(sourceFile) && host.getResolvedProjectReferenceToRedirect(sourceFile.fileName)) &&
+                !host.isSourceOfProjectReferenceRedirect(sourceFile.fileName)
+            ));
     }
 
     export function getSourceFilePathInNewDir(fileName: string, host: EmitHost, newDirPath: string): string {

src/testRunner/unittests/tsbuild/javascriptProjectEmit.ts

@@ -1,5 +1,5 @@
 namespace ts {
-    describe("unittests:: tsbuild:: javascriptProjectEmit:: loads js-based projects and emits them correctly", () => {
+    describe("unittests:: tsbuild:: javascriptProjectEmit::", () => {
         verifyTsc({
             scenario: "javascriptProjectEmit",
             subScenario: `loads js-based projects and emits them correctly`,
@@ -87,12 +87,11 @@ namespace ts {
             }, symbolLibContent),
             commandLineArgs: ["-b", "/src"]
         });
-    });
 
-    describe("unittests:: tsbuild:: javascriptProjectEmit:: loads outfile js projects and concatenates them correctly", () => {
-        let projFs: vfs.FileSystem;
-        before(() => {
-            projFs = loadProjectFromFiles({
+        verifyTscSerializedIncrementalEdits({
+            scenario: "javascriptProjectEmit",
+            subScenario: `modifies outfile js projects and concatenates them correctly`,
+            fs: () => loadProjectFromFiles({
                 "/src/common/nominal.js": Utils.dedent`
                     /**
                      * @template T, Name
@@ -175,30 +174,14 @@ namespace ts {
                             "declaration": true
                         }
                     }`,
-            }, symbolLibContent);
-        });
-        after(() => {
-            projFs = undefined!;
-        });
-        verifyTsc({
-            scenario: "javascriptProjectEmit",
-            subScenario: `loads outfile js projects and concatenates them correctly`,
-            fs: () => projFs,
-            commandLineArgs: ["-b", "/src"]
-        });
-        verifyTscSerializedIncrementalEdits({
-            scenario: "javascriptProjectEmit",
-            subScenario: `modifies outfile js projects and concatenates them correctly`,
-            fs: () => projFs,
+            }, symbolLibContent),
             commandLineArgs: ["-b", "/src"],
             incrementalScenarios: [{
                 buildKind: BuildKind.IncrementalDtsUnchanged,
                 modifyFs: fs => replaceText(fs, "/src/sub-project/index.js", "null", "undefined")
             }]
         });
-    });
 
-    describe("unittests:: tsbuild:: javascriptProjectEmit:: loads js-based projects with non-moved json files and emits them correctly", () => {
         verifyTsc({
             scenario: "javascriptProjectEmit",
             subScenario: `loads js-based projects with non-moved json files and emits them correctly`,